Perception of Musical Emotion in the Students with Cognitive and Acquired Hearing Loss.

Objective
Hearing loss can affect the perception of emotional reaction to the music. The present study investigated whether the students with congenital hearing loss exposed to the deaf culture, percept the same emotion from the music as students with acquired hearing loss.


Materials & Methods
Participants were divided into two groups; 30 students with bilaterally congenital moderate to severe hearing loss that were selected from deaf schools located in Tehran, Iran and 30 students with an acquired hearing loss with the same degree of hearing loss selected from Amiralam Hospital, Tehran, Iran and compared with the group of 30 age and gender-matched normal hearing subjects served our control in 2012. The musical stimuli consisted of three different sequences of music, (sadness, happiness, and fear) each with the duration of 60 sec. The students were asked to point to the lists of words that best matched with their emotions.


Results
Emotional perception of sadness, happiness, and fear in congenital hearing loss children was significantly poorly than acquired hearing loss and normal hearing group (P<0.001). There was no significant difference in the emotional perception of sadness, happiness, and fear among the group of acquired hearing loss and normal hearing group (P=0.75), (P=1) and (P=0.16) respectively.


Conclusion
Neural plasticity induced by hearing assistant devises may be affected by the time when a hearing aid was first fitted and how the auditory system responds to the reintroduction of certain sounds via amplification. Therefore, children who experienced auditory input of different sound patterns in their early childhood will show more perceptual flexibility in different situations than the children with congenital hearing loss and Deaf culture.

of life, infants start vocalization, which can be the precursors of music and speech perception (7). Unfortunately, deprivation of hearing sense and deficient of pitch perception, especially in congenitally deaf children can affect achievement of both perception and production of speech; additionally, skills such as processing of musical aspects and emotional prosody like pitch range, direct and rhythmicity will be too.
Emotional prosody includes semantic information (differences between statement and question) and affective intent (differences between happiness and sadness) is crucial for achieving the meaning of speech and music (8). Deaf children have problems in production of appropriate rate, loudness, stress, and their laryngeal and resonance quality of expressive prosody were defaced. Moreover, they prefer to use vision rather than hearing in situation where both of the modalities are affected (8).
There is a relation between music and emotion. Children with normal hearing react to the music, spontaneously and effortlessly and often have an exciting emotional response (3). As the normal hearing children grow, even ones as young as 3 yr old, can make a link between musical inputs and specific emotion. Different studies pointed that the children similar to adults could judge labels same as happy, sad or angry for classical music segments Children, who experienced auditory input of different sound patterns in their early childhood, will show more perceptual flexibility in different situations. Thus, the purpose of the present study was to investigate whether the students with congenital hearing loss exposed to the deaf culture, percept the same emotion from the music as the students with acquired hearing loss.

Materials & Methods
The study participants were 60 students divided into two groups. The first group consisted of 30 students with bilaterally congenital moderate to severe hearing loss who were studying in deaf cultured high school from deaf schools and

Musical stimuli
The musical stimuli used in this study consisted of three different sequences of music, each with the duration of 60 sec randomly ordered to depict one of the three basic emotions -happiness, sadness, and fear. We incorporated those musical pieces clearly intended their meaning by their composers.

Procedure
Participants were tested in a typical silent room.
Individuals with hearing loss took their hearing aids off. They were seated in front of a

Results
The variables of happiness, sadness and fear did not have statistically significant differences (P>0.05).
There was a significant difference between groups considering their performance on the variables of happiness, sadness, and fear; children with congenital hearing loss performed poorer than those with acquired hearing loss and control group.  Table 1). The results of each of three emotional perception variables in two genders are presented in Table 2.
There were no significant differences in happiness, sadness and fear perception between two genders, meaning that both groups behaved the same in the emotional perception.

Discussion
The purpose of the present study was to investigate whether children with congenital hearing loss with deaf culture had the same emotional reaction to music as children with acquired hearing loss or not.
They did not show the same emotion to the music.
There were significant differences between two groups considering musical perception and more mistakes were seen in children with congenital hearing loss. The children with congenital hearing loss may not listen to the music as well as acquired hearing loss, in spite of receiving suitable hearing aid prescription according to their audiograms.
Listening is a complex task and needs higher level of central auditory processing rather than hearing temporal processing depend on maturation of the central auditory system to adolescence (11).
If children with acquired hearing loss receive enhanced auditory experience in critical periods, it results in shaping the auditory brain function that has an important role in speech processing, cognition, and emotional prosody. Perception of musical emotion in deaf students was investigated.

Results indicated a significant difference between
the deaf and normal hearing participants that was in accordance with our study results. Deaf children were less aware of musical style and most of them received actually no musical training (5).
Cochlear implant (CI) as one of the rehabilitation approach enables many deaf children to achieve more appropriate speech perception and perhaps enjoy the music. However, situation is very different for music perception, because with most CI signal processing strategies, pitch information may be transmitted insufficiently (12). The musical input that implant users receive is different The findings of the present study are in line with previous studies, where found no age and gender effects on musical perception. (5,18,19). Culture and auditory experience can affect the perception of musical emotion. Darrow states that discussion about the emotional aspects of music can also be extended to stimulate the thoughts and feelings that deaf children may experience; additionally, we cannot change the deaf culture, but with incorporating the music, we can increase musical experience of children who received deaf culture (5).
In Conclusion, perception of musical emotion is depended on auditory experience and culture of someone. So the usage of amplification that introduces high resolution and fine temporal cues as soone as possible in children can affect development and integration in central nervous system.

Acknowledgment
Authors thank Alireza Poorjavid for developing of original idea. Mothers and children whose participation made this study feasible are also greatly thanked.

Author`s Contribution
Maliha Mazaher Yazdi: study concept and design, Arjmand: study concept, design and making pieces of emotional music.
All authors agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.